From 4eaad21a6ac9865df7f31983232ed5928450458d Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 20 Jan 2021 21:46:29 +0100 Subject: kernfs: implement ->read_iter Switch kernfs to implement the read_iter method instead of plain old read to prepare to supporting splice and sendfile again. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20210120204631.274206-2-hch@lst.de Signed-off-by: Greg Kroah-Hartman --- fs/kernfs/file.c | 35 ++++++++++++----------------------- 1 file changed, 12 insertions(+), 23 deletions(-) (limited to 'fs') diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index f277d023ebcd..8276e4c8722d 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -14,6 +14,7 @@ #include #include #include +#include #include "kernfs-internal.h" @@ -180,11 +181,10 @@ static const struct seq_operations kernfs_seq_ops = { * it difficult to use seq_file. Implement simplistic custom buffering for * bin files. */ -static ssize_t kernfs_file_direct_read(struct kernfs_open_file *of, - char __user *user_buf, size_t count, - loff_t *ppos) +static ssize_t kernfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) { - ssize_t len = min_t(size_t, count, PAGE_SIZE); + struct kernfs_open_file *of = kernfs_of(iocb->ki_filp); + ssize_t len = min_t(size_t, iov_iter_count(iter), PAGE_SIZE); const struct kernfs_ops *ops; char *buf; @@ -210,7 +210,7 @@ static ssize_t kernfs_file_direct_read(struct kernfs_open_file *of, of->event = atomic_read(&of->kn->attr.open->event); ops = kernfs_ops(of->kn); if (ops->read) - len = ops->read(of, buf, len, *ppos); + len = ops->read(of, buf, len, iocb->ki_pos); else len = -EINVAL; @@ -220,12 +220,12 @@ static ssize_t kernfs_file_direct_read(struct kernfs_open_file *of, if (len < 0) goto out_free; - if (copy_to_user(user_buf, buf, len)) { + if (copy_to_iter(buf, len, iter) != len) { len = -EFAULT; goto out_free; } - *ppos += len; + iocb->ki_pos += len; out_free: if (buf == of->prealloc_buf) @@ -235,22 +235,11 @@ static ssize_t kernfs_file_direct_read(struct kernfs_open_file *of, return len; } -/** - * kernfs_fop_read - kernfs vfs read callback - * @file: file pointer - * @user_buf: data to write - * @count: number of bytes - * @ppos: starting offset - */ -static ssize_t kernfs_fop_read(struct file *file, char __user *user_buf, - size_t count, loff_t *ppos) +static ssize_t kernfs_fop_read_iter(struct kiocb *iocb, struct iov_iter *iter) { - struct kernfs_open_file *of = kernfs_of(file); - - if (of->kn->flags & KERNFS_HAS_SEQ_SHOW) - return seq_read(file, user_buf, count, ppos); - else - return kernfs_file_direct_read(of, user_buf, count, ppos); + if (kernfs_of(iocb->ki_filp)->kn->flags & KERNFS_HAS_SEQ_SHOW) + return seq_read_iter(iocb, iter); + return kernfs_file_read_iter(iocb, iter); } /** @@ -960,7 +949,7 @@ void kernfs_notify(struct kernfs_node *kn) EXPORT_SYMBOL_GPL(kernfs_notify); const struct file_operations kernfs_file_fops = { - .read = kernfs_fop_read, + .read_iter = kernfs_fop_read_iter, .write = kernfs_fop_write, .llseek = generic_file_llseek, .mmap = kernfs_fop_mmap, -- cgit v1.2.3 From cc099e0b399889c6485c88368b19824b087c9f8c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 20 Jan 2021 21:46:30 +0100 Subject: kernfs: implement ->write_iter Switch kernfs to implement the write_iter method instead of plain old write to prepare to supporting splice and sendfile again. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20210120204631.274206-3-hch@lst.de Signed-off-by: Greg Kroah-Hartman --- fs/kernfs/file.c | 28 ++++++++++------------------ 1 file changed, 10 insertions(+), 18 deletions(-) (limited to 'fs') diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index 8276e4c8722d..b1a5cccf189e 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -242,13 +242,7 @@ static ssize_t kernfs_fop_read_iter(struct kiocb *iocb, struct iov_iter *iter) return kernfs_file_read_iter(iocb, iter); } -/** - * kernfs_fop_write - kernfs vfs write callback - * @file: file pointer - * @user_buf: data to write - * @count: number of bytes - * @ppos: starting offset - * +/* * Copy data in from userland and pass it to the matching kernfs write * operation. * @@ -258,20 +252,18 @@ static ssize_t kernfs_fop_read_iter(struct kiocb *iocb, struct iov_iter *iter) * modify only the the value you're changing, then write entire buffer * back. */ -static ssize_t kernfs_fop_write(struct file *file, const char __user *user_buf, - size_t count, loff_t *ppos) +static ssize_t kernfs_fop_write_iter(struct kiocb *iocb, struct iov_iter *iter) { - struct kernfs_open_file *of = kernfs_of(file); + struct kernfs_open_file *of = kernfs_of(iocb->ki_filp); + ssize_t len = iov_iter_count(iter); const struct kernfs_ops *ops; - ssize_t len; char *buf; if (of->atomic_write_len) { - len = count; if (len > of->atomic_write_len) return -E2BIG; } else { - len = min_t(size_t, count, PAGE_SIZE); + len = min_t(size_t, len, PAGE_SIZE); } buf = of->prealloc_buf; @@ -282,7 +274,7 @@ static ssize_t kernfs_fop_write(struct file *file, const char __user *user_buf, if (!buf) return -ENOMEM; - if (copy_from_user(buf, user_buf, len)) { + if (copy_from_iter(buf, len, iter) != len) { len = -EFAULT; goto out_free; } @@ -301,7 +293,7 @@ static ssize_t kernfs_fop_write(struct file *file, const char __user *user_buf, ops = kernfs_ops(of->kn); if (ops->write) - len = ops->write(of, buf, len, *ppos); + len = ops->write(of, buf, len, iocb->ki_pos); else len = -EINVAL; @@ -309,7 +301,7 @@ static ssize_t kernfs_fop_write(struct file *file, const char __user *user_buf, mutex_unlock(&of->mutex); if (len > 0) - *ppos += len; + iocb->ki_pos += len; out_free: if (buf == of->prealloc_buf) @@ -662,7 +654,7 @@ static int kernfs_fop_open(struct inode *inode, struct file *file) /* * Write path needs to atomic_write_len outside active reference. - * Cache it in open_file. See kernfs_fop_write() for details. + * Cache it in open_file. See kernfs_fop_write_iter() for details. */ of->atomic_write_len = ops->atomic_write_len; @@ -950,7 +942,7 @@ EXPORT_SYMBOL_GPL(kernfs_notify); const struct file_operations kernfs_file_fops = { .read_iter = kernfs_fop_read_iter, - .write = kernfs_fop_write, + .write_iter = kernfs_fop_write_iter, .llseek = generic_file_llseek, .mmap = kernfs_fop_mmap, .open = kernfs_fop_open, -- cgit v1.2.3 From f2d6c2708bd84ca953fa6b6ca5717e79eb0140c7 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 20 Jan 2021 21:46:31 +0100 Subject: kernfs: wire up ->splice_read and ->splice_write Wire up the splice_read and splice_write methods to the default helpers using ->read_iter and ->write_iter now that those are implemented for kernfs. This restores support to use splice and sendfile on kernfs files. Fixes: 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops") Reported-by: Siddharth Gupta Tested-by: Siddharth Gupta Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20210120204631.274206-4-hch@lst.de Signed-off-by: Greg Kroah-Hartman --- fs/kernfs/file.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs') diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index b1a5cccf189e..c75719312147 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -949,6 +949,8 @@ const struct file_operations kernfs_file_fops = { .release = kernfs_fop_release, .poll = kernfs_fop_poll, .fsync = noop_fsync, + .splice_read = generic_file_splice_read, + .splice_write = iter_file_splice_write, }; /** -- cgit v1.2.3